1. Field of Invention
The present invention relates generally to aquatic environmental toxicology assay systems, and particularly to a device and method which automatically monitors the movements of living organisms exposed to a plurality of concentrations of a substance or sample, and rapidly quantifies the level of toxicity of the substance or sample by analyzing said movements. The present invention also relates to systems for quantifying air quality.
2. Prior Art
Toxicity is defined as a biological effect, specifically it is the concentration of a substance which causes a certain level of adverse effect on living organisms. It is desirable to quantify the toxicity of an effluent or of any material which may enter a water body. Knowing the concentration which is toxic defines the limit for releasing that material to prevent organisms in the water body from an adverse effect. It is also desirable to know if toxic concentrations have been reached in a receiving water. This information helps to identify polluters and it helps dischargers innocent of toxic pollution to escape legal penalties.
Most prior art aquatic environmental toxicology systems, generally termed automated biological monitoring systems (ABMS), are designed to rapidly detect the presence of toxicity in an aqueous environment, especially in water supplies, or in waste-waters and effluents, or receiving waters. The usual purpose of these systems is to provide an early warning of the presence of toxicity. Many of these systems use a computer interfaced device which senses and interprets movement of aquatic organisms to detect toxicity. However, unlike the present invention, these systems can not quantify toxicity because this would require monitoring a plurality of sample concentrations at one time. This is not their purpose and this is not supported by their design. Examples of patents for this type of invention are awarded to John Greaves in 1986, U.S. Pat. No. 4,626,992; and Solman, et.al. (1988), U.S. Pat. No. 4,723,511. The scientific literature describing automated biological monitoring systems (ABMS) designed to rapidly detect the presence of toxicity (but not to quantify it) is also extensive. Some examples are:
Cairns, J. (1988) Validating biological monitoring. in: Automated Biological monitoring: living sensors as environmental monitors, Gruber, D. S. and J. M. Diamond (eds), Ellis Horwood Ltd, Chichester! PA1 Cairns, J. Jr., 1990. The Genesis of Biomonitoring in Aquatic Ecosystems. The Environmental Professional: the official Journal of the National Association of Environmental Professionals (NAEP), Pergamon Press, vol 12, 1990 p. 169-176.! PA1 Cairns, J. and van der Schalie, W. H. (1980) Biological Monitoring Part I--Early Warning Systems. Wat. Res. 14, 1179-1196. PA1 Diamond, J. M., M. J. Parson, and D. Gruber. 1990. Rapid detection of sublethal toxicity using fish ventilatory behavior. J. Environ. Tox. Chem. 9:3-11; PA1 Drummond, R. A. and Carlson, R. W. (1977) Procedures for measuring cough gill purge rates of fish. EPA 600/3-77-133. Environmental Protection Agency, Washington, D.C. PA1 Gruber, D. C. H. Frago and W. J. Rasnake. Automated biomonitors--first line of defense. J of Aquatic Ecosystem Health 3:87-92, 1994 PA1 Gruber, David, J. M. Diamond, M. J. Parson. "Automated Biomonitoring". Environmental Auditor, Vol 2, No. 4. pp. 229-238. 1991 Springer-Verlag New York Inc.! PA1 Korver, R. M. and J. B. and Sprague, 1988. A real-time computerized video tracking system to monitor locomotor behavior. In: D. S. Gruber and J. M. Diamond (eds). Automated biomonitoring: living sensors as environmental monitors. pp. 182-205. Ellis Horwood Ltd, Chichester PA1 Kramer, K. J. M., H. A. Jenner and D. Zwart, 1989. The valve movement response of mussels: A tool in biological monitoring. Hydrobiologia 188/189 (Dev. Hydrobiol, 54:433-443. PA1 Miller, D. C., Lang, W. H., Greaves, J. O. B., and Wilson, R. S. (1982). Investigations in aquatic behavioral toxicology using a computerized video quantification system. ASTM STP 766. American Society for Testing and Materials, Philadelphia. PA1 Poels, C. L. M. 1975. Continuous automatic monitoring of surface water with fish. Water Treatment Examination 24: 46-56. PA1 Sherer, E. and Nowak, S. (1973) Apparatus for recording avoidance movement of fish. J.Fish Res. Board Con. 30 1594-1596 PA1 Smith, E. H. and H. C. Bailey, 1988. Development of a system for continuous biomonitoring of a domestic water source for early warning of contaminants. In: D. S. Gruber and J. M. Diamond (eds). Automated biomonitoring: living sensors as environmental monitors. pp. 182-205. Ellis Horwood Ltd, Chichester PA1 for performing and for rapidly predicting the results of acute and chronic conventional laboratory toxicity tests (CLTT's) such as those described in the U.S Environmental Protection Agency publication EPA/600/4-90/027F, AUGUST 1993. PA1 for correlating early motility data with the lethality end point of conventional laboratory toxicity test data. PA1 for quantifying behavioral observations made for conventional laboratory toxicity tests. At present these observations made in such tests are subjective, based on the opinion and perspective of a single person observing the organisms. On the other hand, the rate of movement determined with this invention would be a useful objective observation. PA1 for rapidly performing range finding tests. Range finding tests are performed to determine the range of concentrations of liquid which should be used in a conventional laboratory toxicity test. In effect they are a mini-toxicity test which may take a day or more for results to become available. This invention can speed range finding tests and reduce the time needed to get results to a few hours (usually within three hours).
There are other prior art aquatic environmental toxicity test systems that do quantify toxicity. They use methods other than motility to indicate a toxic effect. The Microtox system (Azur Environmental Inc.) described by Bulich (ref: Bulich, A. A., 1979. Use of luminescent bacteria for determining toxicity in aquatic environments. In: L. L. Murking and R. A Kimerle (eds). Aquat. Toxicol. ASTM STP 667:98-106.) uses a bioluminescent bacterium as a test organism. The fluorescent aquatic bioassay procedure patented by Hayes (1990), U.S. Pat. No. 5,094,944, uses chemically induced fluorescence in a variety of organisms as an indicator of toxicity.
The Microtox system quantifies toxicity by measuring the effect of a toxic liquid on bioluminescence in a particular bacterium. The value of this system is limited because only a particular bacterium may be used for the assay, and the equipment and cost per test is expensive. Because bacterial physiology is significantly different from that of higher organisms the Microtox response to a substance or sample does not necessarily reflect the toxicity response of higher aquatic organisms which may be important living components of aquatic environments. The Microtox system is further limited because the level of toxicity for the test bacterium may be different from that of larger motile aquatic organism which have a completely different physiology. Therefore the Microtox system may not accurately reflect the danger to aquatic organisms and ecosystems which the tested substance may pose.
The fluorescent aquatic bioassay procedure patented by Hayes (1990) requires that the test organism be fed a compound which carries a fluorescent marker. Generally, introducing materials to test organisms, if other than those specifically indicated by a conventional laboratory toxicity test (CLTT) protocol is prohibited by these protocols, and this invalidates the test. This is one reason the US Environmental Protection Agency does not accepted this test as a standard. These materials may interfere with the accuracy of the toxicity test and therefore invalidate the results, and there is a general prohibition against using extraneous chemicals in most US EPA toxicity testing protocols.